Application and set-up error of deep inspiration breath-hold (DIBH) technique for whole breast irradiation in left breast cancer
10.3760/cma.j.issn.1004-4221.2018.05.014
- VernacularTitle:左侧乳腺癌保乳术后采用深吸气屏气放疗技术的应用与摆位误差
- Author:
Siye CHEN
1
;
Shulian WANG
;
Yu TANG
;
Yuan TIAN
;
Shirui QIN
;
Weijie CUI
;
Jing JIN
;
Yueping LIU
;
Yongchun SONG
;
Hui FANG
;
Bo CHEN
;
Shunan QI
;
Jianghu ZHANG
;
Guangyi SUN
;
Yanbo DENG
;
Yexiong LI
Author Information
1. 国家癌症中心/中国医学科学院北京协和医学院肿瘤医院放疗科
- Keywords:
Breast neoplasm;
Radiotherapy dosage;
Deep inspiration breath-hold technique;
Setup error
- From:
Chinese Journal of Radiation Oncology
2018;27(5):504-508
- CountryChina
- Language:Chinese
-
Abstract:
Objective To analyze the correlation between treatment time and radiotherapy plan of deep inspiration breath-hold (DIBH) technique for the whole breast irradiation (WBI) in the left breast cancer after breast-conserving surgery,verify the inter-fractional reproducibility of radiotherapy,observe the heart location and dosimetric changes and calculate the effect of DIBH upon the WBI setup error after the surgery.Methods We prospectively enrolled 15 patients with left breast cancer undergoing WBI after breast-conserving surgery,who met the requirement of D1BH.Treatment time was recorded,its correlation with the number of field and monitor unit was analyzed.Inter-fractional setup errors and PTV delineation were calculated using cone beam CT (CBCT).The accuracy of the position and dose of the heart during radiotherapy was verified by the imaging fusion of CBCT and CT images.The variables among groups were analyzed by non-parametric Firedman test.Results The average treatment time of DIBH radiotherapy was 4.6 minutes.The treatment time was correlated with the maximal and total number of sub-fields and total monitor units.During DIBH treatment,the mean cardiac displacement volume was 19.1 cm3(3.8％).The mean cardiac dose difference between CBCT and planning CT was 5.1 cGy,and there was no significant difference in the heart V5-V30.The mean inter-fractional system setup error (∑) and random setup error (σ) in the left-right (x),superior-inferior (y) and anterior-posterior (z) direction were ∑x 1.9 mm,∑y 2.1 mm,∑z 2.0 mm,σx 1.3 mm,σy 1.3 mm,σz 1.4 mm,respectively.The corresponding minimal margins for setup error were 5.7 mm,6.2 mm and 6.0 mm,respectively.Conclusion DIBH for WBI after breast-conserving surgery does not significantly prolong the treatment time.Treatment time is related to treatment plan.DIBH yields high inter-fractional reproducibility and protects the heart.
